The
Laboratory is a leader in separation technologies for producing
hydrogen. ORNL is the lead Department of Energy laboratory
in studying hydrogen delivery and ranks third in DOE funding
for research on vehicular fuel cells.

To
produce hydrogen, ORNL is developing both microporous and
proton separation membranes supported on porous metallic
tubes. These membranes could separate hydrogen from carbon
monoxide in syngas produced by coal gasification. The microporous
membrane is derived from the declassified inorganic membrane
developed to enrich uranium in its fissionable isotope at
the old Oak Ridge Gaseous Diffusion Plant. A team led by
Armstrong has developed a new proton conductor, a ceramic
oxide, that enables hydrogen to diffuse rapidly through it
at temperatures less than 700°C, where most conventional
proton-conducting oxides operate. "Our material works at
500°C," Armstrong says. "This is the 'sweet spot' for
separating hydrogen from coal gas."

Hydrogen
also can be produced from natural gas and petroleum. To generate
pure hydrogen, sulfur must be removed from these fossil fuels.
ORNL and DOE's National Energy Technology Laboratory have
developed a way to remove sulfur from hydrogen sulfide (H2S)
gas streams using a carbon-based catalyst.

The ORNL catalyst
can remove both carbonyl sulfide (COS) and H2S,
making it ideal for separating sulfur from coal gas; the
sulfur-free gas can be a source of pure hydrogen for fuel
cells. This sulfur-removal method has attracted the interest
of General Electric, Chevron Texaco, and Conoco Phillips.

A
team led by ORNL's James Lee seeks to produce hydrogen biologically.
The project focuses on engineering wild algae's genetic structure
and adding a proton channel to increase the algae's hydrogen
production efficiency 10 to 100 times, possibly creating
a renewable hydrogen resource.

For
hydrogen delivery, ORNL researchers are developing and examining
materials for pipes and welds that exhibit a very low hydrogen
diffusion, or leak rate. The goal is to replace today's current
natural gas pipeline materials with metallic systems and
to improve welds, which are potential failure points in pipelines.

A
new ORNL project would reduce the number of welds by adding
distance between them while simplifying the assembly process.
The goal is to develop a "smart" pipeline consisting of an
extruded polymer pipe liner reinforced by a carbon fiber
tow. The tow is integrated with leak sensors and failure
sensors before being wrapped.

Jim
Hardy's team at ORNL is developing a cost-effective, portable
acoustic sensor to detect leaks from hydrogen gas pipelines.
The researchers are also developing a fiber-optic–based
hydrogen safety sensor that will monitor the pressure of
compressed hydrogen in the fuel tanks of future fuel-cell–powered
vehicles.

ORNL's
Tim McIntyre leads a team devising a fiber-optic–based
sensor to monitor the temperature and humidity in fuel cells.
Measurements of inlet and outlet gas parameters will be used
to validate computer models of fuel cell performance. These
sensors will become an integral part of a fuel-cell control
system.

Recently,
a carbon-based bipolar plate developed by ORNL's Ted Besmann
was licensed to Porvair for commercialization. Mike Brady
has since developed a new metal bipolar plate for proton-exchange-membrane
(PEM) fuel cells. "The plate has very high electrical conductivity
and has shown no corrosion up to 5000 hours," says Armstrong. "We
are partnering with fuel-cell manufacturers and automakers
to develop further this and other ORNL technologies."